Wycech, Meson Testing Λ(1405) with K-mesic atoms S.Wycech IPJ, Warsaw The purpose Λ(1405) is the dorway and the mechanism to bind the „K-mesic nuclei”

Wycech, Meson Two approaches to Λ(1405) Phenomenology K – matrix fitted to data + dispersion relations Extrapolation below KN, E ~ 1405 MeV PDG, R.Dalitz, A.Martin.. many others since 1970 ▪ Chiral models SU(3) symmetric driving force, pole in Σ π, pole in KN plane, E ~ 1420 MeV W.Weise, E.Oset.. others since 2000

Wycech, Meson Experimental check K N  Σ π below threshold in final states not conclusive provides amplitude a(K N, Σ π) no a(K N,KN)

Wycech, Meson- 2010

Two new (?) suggestions to extract KN amplitudes from 1)Upper atomic levels 2) Atomic  nuclear radiative transitions

Wycech, Meson „upper levels „ s p d …. n= 3 n= 2 „ upper ” n= 1 „ lower „

Wycech, Meson Upper levels „do not fit „ E. Friedman, A.Gal Im a= 0.37 fm upper levels Im a= 0.94 fm lower levels Г ~ Im a (KN, E = - EBINDING - ERECOIL ) % accurate in upper levels impulse approx. not valid in lower levels

Wycech, Meson Nucleon levels „seen” in atoms V(r) radial distance lower upper levels

Wycech, Meson Parallel case, antiprotonic atoms Nuclear regions studied in atomic levels lower upper cold capture ↓ ↓ ↓ ρ(r)

Wycech, Meson P-bar N subthreshold energies involved in p-bar atoms MeV P D T He 4

Wycech, Meson Im a(E) extracted from light antiprotonic atoms - PS 207 data Paris model

Wycech, Meson Im a KN (E) extracted from upper widths

Wycech, Meson Im a(KN) extracted from upper widths

Wycech, Meson Favorite situation for studying Г(upper): one or few nucleon orbitals perfect P,D,He, very good Li, Be, C, N,O, resonable in almost all atoms

Wycech, Meson K-neutron dominated widths Upper widths due mostly to Kn, S + P wave Pb  Im a (K – n) Apparently dominated by Σ (1385)

Wycech, Meson Another possibility to study sub-threshold elastic KN or K-nucleus amplitude

Wycech, Meson K-hydrogen  Λ(1405 ) + γ Kaons lost in cascade Kaonic Hydrogen ~ 95% lost How many go to Λ(1405 ) + γ ?

Wycech, Meson Old BNL experiment K – p  Σ(1190) γ Found on the level of 1/1000 D.A.Whitehouse..PRL.63(89)1352; K.D.Larsen.. Phys.Rev D47(93)799 K – p  Λ(1405) γ Is it feasible ? What is the line shape ?

Wycech, Meson High energy photons from K - p atom

Wycech, Meson Gamma rays to Λ(1405) of captures from ( n P) levels s p d n= 3 n= 2 n= 1 Λ(1405)

Wycech, Meson Occupation and capture from all (n,P) states estimated captures from n P states in gas targets ~ few % of stopped K mesons Total chance for γ transition ~ per stopped kaon

Wycech, Meson Kaonic deuterium atom  KNN Deep state ~100 MeV ( FINUDA, DISTO) Very small chance Weakly bound or virtual state ~ 47 MeV P+ Σ(1385) sw Phys. Rev C 79 Good chance

Wycech, Meson Line shape Г = ∫ dk S(k) S(k) = Im T KN,KN (E o –k) k G KN (k)

Wycech, Meson LINE SHAPE resonance●propagator●phase space Σ π T G KN γ p K -

Wycech, Meson Summary Upper widths in K atoms may determine Im T KN,KN (M K + M N – E ) for E = MeV K -Atom  K-Nuclear + γ may give elastic Im T KNUCLEUS (M K + M N – E ) Experiments are difficult

Wycech, Meson- 2010

Upper levels –suggestions Interesting measurements He (2p ) Be, C, repetition Sn 112,116,118,124 – different proton bindings Pb 208 Kn parameters in addition to D